The goal of this research program is to extend the usefulness of electroencephalographic evoked potentials as a nonivasive means of estimating cortical responses of the brain and thereby to increase its value as a measurement and analysis tool in research on human development and function. This will be accomplished through the continuing development of special signal measuring and processing techniques capable of providing quantitative estimates of parameters associated with individual responses and components of individual responses as opposed to the averaging techniques widely employed at the present time. The continued investigation of the signal processing techniques developed in this laboratory such as the latency corrected average (LCA), minimum mean square error filter and the extension of these techniques will be a primary objective of this project. Another goal of this research project will be the utilization of more powerful signal processing techniques based on signal space concepts for optimum processing of single event related potentials. The sensitivity aforded by these techniques will permit improved differentiation between responses to different stimuli, a more exact determination of stimulus parameter variations and more sensitive description of the stability of the evoked potential over a period of time.